Apparatus for refining and desilverizing lead.



Parented Nov. 27, |900. S. TBEDINN-ICK. APPARATUS FOR REFINNG ANDDESILVERIZING LEAD.

(Application led Apr. 2, 1900.)

2 Sheets-Shaat l,

(No Medel.)

No. 662,836'. Patented Nov. 27, |900;

S. THEDINNICK. APPARATUS FOR REFINING AND DESILVERIZING LEAD.

(Appuceian med Apr. 2, 1'900.

@No Model.;

2 Smets-Sheet 2.

STEPHEN TREDINNIOK, OF BUTTE, MONTANA, ASSIGNOR OF ONE-FOURTH TO ADOLPHWETZSTEIN, OF SAME PLACE.

APPARATUS FOR REFINING AND DESILVERIZING LEAD.

SPECIFICATION forming' part Of Letters Patent N0. 662,836, datedNovember 27, 1900.

Application filed April 2, 1900. Serial No. 11,275. (No model.)

To all whom, it may concern.-

Be it known that I, STEPHEN TREDINNICK, a citizen of the United States,residing at Butte, in the county of Silver Bow and State of Montana,have invented certain new and useful Improvements in Apparatus forRefining and Desilverizing Lead; and I do declare the following to be afull, clear, and exact description of the invention, such as will enableothers 1o skilled in the art to which it appertains to make and use thesame.

My invention relates to improvements in apparatus for refining anddesilverizing lead, and particularly to lead reining and desilverizingapparatus of the type shown in patents t-o Gustave Luce, No. 144,993,dated November 25, 1873, and No. 152,906, dated July 14, 1874. In thistype of apparatus the crude argentiferous lead is melted down in avessel 2o heated by a fire and provided at its lower end with a spoutclosed with a slide, through which when the lead is melted it is causedto ow down into a lower crystallizing vessel or vat. When the lowervessel is full, steam is introduced through a central pipe leading downto near the bottom of the vessel, where it is provided with a valve andwith a bafdeplate for dividing the steam as it enters. The steam inpassing up through the molten lead 3o effectually oxidizes allimpurities, which then rise in the form of scum to the top of the metal,whence they are removed. The introduction of the steam at the same timeproduces a violent ebullition of the lead, causing 3 5 it tocrystallize, and when this crystallization has taken place to asufficient extent the introduction of steam is stopped by closing thevalve in the steam-pipe, and the remaining liquid portion of the lead,in which the greater 4o proportion of the silver will be foundconcentrated, is run off through one or more spouts into troughs forconducting the lead into ingot-molds. During this time a fresh charge oflead containing a percentage of silver approximating to that of thecrystals in the lower vessel has been melted down in the upper vesseland is run into the lower vessel as soon as all the liquid portion hasbeen removed therefrom. Steam is then again in- 5o troduced, effecting afurther purification and separation of silver, and this process iscontinued until by the repeated crystallization one part of the lead isrendered comparatively free from silver to be used as merchant lead,while the lead run off is sufficiently rich in silver for the cupelingprocess.

The object of my invention is to provide an apparatus whereby theseveral operations incident to the process may be performed in amorethorough and expeditious manner than 6o heretofore, economy in stock,labor, and fuel effected,-and a proportionately larger quantity ofmaterial treated in a given period of time; and to this end it consistsof certain novel features of construction, combination, and arrangementof parts, as will be hereinafter more fully described, and particularlypointed out in the appended claims.

In the accompanying drawings, Figure 1 is a top plan View of anapparatus constructed 7o in accordance with my invention, showing fiveof a series of twelve kettles. Fig. 2 is a side elevation of the same,showing two of the kettles in vertical section. Fig. 3 is an enlargeddetail sectional view of one of the kettles, the section being taken atright angles to that shown in Fig'. 2, showing also the expansion-joint,downtake-flue, and common underground flue for the discharge of thesmoke and products of combuston from all 8o the kettles. Fig. 4 is ahorizontal section of the same on the line of the ash-pit of the kettle.

Referring now more particularly to the drawings, in which likereference-letters designate corresponding parts throughout the severalviews, the letter A designates a series of kettles corresponding innumber to the number of operations necessary to concentrate ordesilverize the lead to the de- 9o sired degree. In practice I preferto'employ a series of twelve kettles, of which five (designateda,a2,a3,a4,and c5) are shown in the present instance. It is desirable toconcentrate a part of the argentiferous lead to five hun 95 dred ouncesof silver per ton and to desilverize the remainder to from one-half toone fourth of an ounce of silver to the ton, the result depending uponthe number of crystallizing operations to which the silver is Ioosubjected, eleven such operations being necessary to secure the former,and twelve oper ations to secure the latter, result. The kettles arearranged in line in a pit and are similar in form and construction, sothat a description otone'will suffice for all.. Each kettle,therefore,comprises an outer inclosing furnace B and a vat or crucible C containedtherein, said furnace being provided with an ash-pit e, grate h, andash-pit and fire doors e and h'. Air for supporting combustion isadmitted to the ash-pit through the door thereof in the usual way, andtlues 7a are provided to allow the heated air, smoke, and products ofcombustion to pass upward and around the vat before discharging. Thefurnace is provided at top with a platform p for the crystallizer towork on,the term crystallizer as used in this connection meaning theperson or individual operating the kettle.

b and b' are two series ofdoors in the sides and top of the vat abovethe platform p. Through the doors l) the crystals, after having beenmelted into liquid form, are introduced into the kettles, while thebullion is worked through the doors b.

d are outlets at opposite sides of the lower end of the vat C and towhich are applied removable spouts e, through which the liquid contentsof the vat are run out, each of said outlets having a screen d toprevent the escape of the solid crystals. The spouts c are adapted to beplaced in position when necessary to connect an intermediate kettle, asa4, wit-h two adjacent kettles, as a3 a5. It will be noted that thedoors b b are two in number on one side of the kettle with but oneoutlet d between them, while at the opposite side of each kettle twooutlets d and spouts c and but one door are employed, this arrangementcontinuing throughout the series ot' kettles. In my construction all theliquid is run out at one side of each kettle, and the purpose of theaforesaid arrangement of the discharge-spouts is to provide for thequick discharge of the liquid through the two spouts c at one sidewithout disturbing the crystals, which when melted are to be dischargedthrough the single spout at the opposite side.

fis a steam-nozzle through which steam is admitted to the vat from asteam-pipe s, and j" is a baille-plate to distribute the steam throughthe mass oi' material in the kettle.

u is a valveV which regulates the supply of steam from the pipes to thenozzle j'. The pipe s receives steam from a suitable source of supplyand supplies each of the kettles, each kettle having its nozzle andcontrollingvalve.

The kettles are mounted to move in guides g, terminating at their upperends in line with the oor or ground, and are adapted to be raised andlowered independently, each being mounted upon a plunger r, movable inacylinder r,the latter being provided at its lower end with a port i3for the ingress and egress of water or other iiuid agent. The nozzles ofthe vats of the several kettles are connected to the steam-pipe s byexpansion-joints to permit the kettles to be raised and lowered whennecessary by the hydraulic cylinders, each ot' said expansion -jointsconsisting of telescoping pipes s' and s2, the pipe s being inovablymounted in the pipe s2 and having a steamtight connection therewith. Thesmoke and products of combustion pass out of the kettle through adowni'lue 7c', having an upwardlybent upper end 752, movably mounted todischarge in an underground iiue or conductor K. This ilue or conductorK receives the discharge of smoke and products of combustion from allthe furnaces of the kettles and is in practice connected at somesuitable point'with a smoke-stack discharging to the atmosphere. y Themechanism for supplying iiuid to and exhausting it from the cylindersfor raising and lowering the kettles comprises a supplytank z2,connected with a pumpfy, which forces the water or other fluid into anaccu mulator e. This accumulator is connected by a pipe z' with asupply-pipe w, having a series of branches i, leading to the ports t3 ofthe cylind'ers, each of said branches being provided with a valve c forcutting off and letting on the flow of water and whereby water may beadmitted to either cylinder independently of the others. Connected tothese supply-pipe branches t' are branch .pipes t", leading' from areturn-pipe w, connected with the tank z2. These branches t" are eachprovided with a valve x for cutting off the return flow of water. Insupplying water to either one or all of the cylinders or any desirednumber of them one, all, or the required number of the valves i; areopened, and the water enters the cylinders through the branchest andportsvl. To exhaust the water to lower the cylinders, the valves c areclosed and the valves as opened, and the water flows from thecylinders,thro ugh ports libi-anches@and branches i', to the common.return-pipe w, and thence back into the tank z2 to be again used.

ln the practical operation ofthe apparatus, assuming that the kettlesci', a3, and a5 are elevated, charged, and ready to be operatedupon tocrystallize the contents and the intermediate kettles 0.2 a4 empty andlowered to receive the enriched liquid therefrom, the lead containedwithin the kettles a', a3, and d5 is reduced to a molten state and thetire then drawn to `allow the lead to cool. At this time a jet of wateris run through the cover of each of these kettles to agitate the moltenlead, so as to produce crystallization in proportion as the temperaturedecreases, and steam is admitted through the nozzlef to prevent thecrystals so formed from settling on the bottom of the vat. 1n passingthrough the molten metal the steam is decomposed and produces oxids oflead, antimony, and copper, according to the degree of impurity of thelead. The oXids rise to the surface of the bath, whence they areremoved. When the proportion of lead crystals appears to besufticient-thatis, when the charge is of a IOO IIO

consistency of two-thirds crystals and onethird liquid-the jet of waterand current of steam are shut off and the liquid run off through theoutlets CZ and spouts c from the elevated kettles to the empty loweredkettles-for instance, from one of the kettle-s a3 or a5 into theintermediate kettle a4. In practice three only of the entire series oftwelve kettles are operated at one time to discharge the crystallizedcontents of one kettle and enriched liquid from the other kettle, and soon continuously throughout the series, the enriched liquid running inone direction and the desilverized lead in the other direction as theoperation progresses. Assuming that. the liquid is being carried towardthe end kettle a and the lead toward lthe opposite end kettle al? (notshown) of the series, the elevated kettles are alternately operated, thecrystallizing process being elfected in onesay, kettle @t5-while thecharge of lead or the lead crystals are being melted in the nextadjoining elevated kettle-say, the kettle a3- and the intermediatekettle a4 receives the enriched liquid from the former4 and thedesilverized melted lead from the latter. The one-third liquid of kettlea runs out through the pair of spouts c on one side is enriched lead andcupeled, while the two-thirds crystals remaining therein after beingmelted are run out through the one spout d on the other side into kettlea2. The one-third liquid of a3 will be of the same grade of bullion asthe two-thirds crystals of a and is run into kettle a2, completing thecharge of same. The two-thirds crystals of kettle a3 after melting isrun into kettle a with the one-third liquid of kettle d5, which is thesame grade of bullion and will complete the charge of kettle a4. Kettlescl2 and a4 are now charged and raised and ready to be operated, whilekettles a', d3, and a5 are empty and lowered to be again charged in likemanner, and so on throughout the series. As stated, of the Whole seriesof twelve kettles only three will be operated on at one time, while thecrystals of the three kettles previously operated on are being melted.With low-grade bullion the separation is half or double-viz., theone-third liquid is double as rich as the original charge and thetwo-thirds crystals are reduced to half the richness of the originalcharge. With high-grade bullion the one-third bullion gains onethirdinstead of one-half in richness.

It will thus be seen that the operation is continuous, resulting in theproduction by gradual decrease in the percentage of silver of merchantlead on the one hand and of lead ready for the cupeling process on theother hand. By thus making the operation continuous I obviate thenecessity of running the lead into molds and remelting it at eachoperation, and consequently effect a saving in fuel, time, and labor.

Having thus fully described my invention, what I claim as new anduseful, and desire to secure by Letters Patent of the United States, is-

l. An apparatus for reining and desilverizing lead, comprising a seriesof kettles, means for connecting the kettles for effecting the dischargeof the contents of one into another, hydraulic cylinders on which thekettles are mounted, a iuid-tank, a pump, connections between the tankand pump and pump and cylinders to supply fluid to raise the cylinders,and connections for exhausting the fluid from the cylinders back to thetank, substantially as set forth.

2. An apparatus for rening and desilven izing lead, comprising a seriesof kettles adapted to communicate one with the other, means for raisingand lowering the kettles, nozzles for injecting a current of steam orthe like into the kettles, a steam-pipe, and eX- pansion-joints betweenthe nozzles and steampipe, substantially as set forth.

3. An apparatus for refining and desilverizing lead, comprising a seriesof independently-movable ,kettles, and hydraulic mechanism comprisingcylinders, a source of fluidsu'pply, and supply and return connectionsfor raising and lowering the kettles, said connections being valved forcontrolling the supply or exhaust to and from one, all or any desirednumber ofl the cylinders, substantially as set forth.

4E. In an apparatus for desilverizing and relining lead, a series ofkettles having inlet and outlet passages, removable spouts forconnecting the outlet-passage of one kettle with the inlet-passage ofanother kettle, and means for raising and lowering the kettles,substantially as set forth.

In testimony whereof I have hereunto set my hand in presence of twosubscribing witnesses.

STEPHEN TREDINNICK.

Witnesses:

F. E. CURTIS, D. S. SHAFFER.

IOO

